You search by county. Just google the county that you're interested in and "tax auction" and you will find the website.
Most NY tax delinquent properties getting auctioned are seriously distressed and troublesome. If you win a bid, you are inheriting an expensive headache, a safety concern, and a tax liability. These are properties where the owners let them go to tax auction for a reason. There is usually something seriously wrong with them. I don't recommend you bid on any as a new person. Watch them for a couple years first.
I think long island sells tax deeds, but I'm not as familiar with those.